The present invention relates to a hand truck for moving a load by hand, provided with a platform for accommodating a load, an operating construction that extends from a first end close to the platform to handles, for grasping the hand truck with the hands, and wheels for moving the hand truck, wherein the hand truck further comprises a pusher plate which can be moved across the platform, for pushing a load placed on the platform off said platform.
A hand truck of the type mentioned in the preamble is known from the prior art. Such a hand truck is disclosed, inter alia, in U.S. Pat. No. 3,844,431. This U.S. patent discloses a hand truck which is provided with a pusher plate that is connected with the aid of arms to the operating construction of the hand truck. The pusher plate can be moved across the surface of the platform by actuating a control element using a foot. Because the element has to be operated by foot, the user is pushed backwards. That is to say the user has to hop backwards on one foot whilst he/she operates the control element with the other foot.
Another variant of a hand truck of the type mentioned in the preamble is disclosed in U.S. Pat. No. 5,599,156. According to this US document the hand truck comprises a first bracket which is provided at the bottom with a platform and with wheels. The pusher plate can be activated with the aid of a second bracket. The second bracket is operated by hand. That is to say there are in fact two operating constructions which extend over virtually the entire length of the hand truck. The presence of the two operating constructions makes the hand truck not only expensive but also heavy. Furthermore, the pivot point about which the second bracket pivots moves downwards towards the pusher plate when the second bracket is actuated. Therefore the user has to bend down a long way when he/she wishes to actuate the pusher plate.
In view of the above, the aim of the present invention is to provide a hand truck of the type mentioned in the preamble with which the construction of the hand truck can be kept relatively simple so that the hand truck itself can be made relatively lightweight and inexpensive.
This aim is achieved in the present invention in that the hand truck comprises a frame to which the platform and the wheels are attached and in that the operating construction is hingeably connected to said frame, wherein the pusher plate on one side is hingeably connected to the first end of the operating construction and on the other side is hingeably connected to the frame via an auxiliary arm.
What is achieved as a result of the fact that the operating construction is able to pivot about the frame and the fact that the hub plate is connected to the end of the operating construction is that the pusher plate can be moved across the platform with an advantageous lever ratio. Furthermore, it is ensured that only a single embodiment of the operating construction is needed and the pusher plate can nevertheless be moved by hand over the surface of the platform. This means that the hand truck according to the invention is easy to operate and, moreover, is relatively lightweight.
According to the invention it is possible for the hand truck to comprise locking means for impeding the hinging movement of the operating construction with respect to the frame, as desired.
What is achieved as a result of this measure is that the hand truck can be used with locking engaged, that is to say safely, for moving loads. When the load has reached its destination, the locking is released and the pusher plate can be activated.
Furthermore, it is possible for the operating construction to be attached to the frame via a first axis, the top edge of the pusher plate being attached such that it can pivot about a second axis parallel to the first-mentioned axis, to the one ends of two parallel legs of an auxiliary frame, the other ends of which are provided with guide elements which run in guide paths in or on the said frame parts, the legs of said auxiliary frame being fixed between the two ends such that they can pivot about a third axis parallel to the first-mentioned axis, to the legs of the operating construction, and for the said bottom ends of the operating construction to be provided with guide elements which run in guide paths in or on the side edges of the pusher plate.
By means of this construction it is ensured that the pusher plate always remains in a position essentially at right angles to the platform, irrespective of the position of the operating construction. As a result, and because the pusher plate has a large surface area, the force of the pusher plate acts on a larger surface of the goods and these will less rapidly become deformed and damaged.
In a preferred embodiment the wheels can each rotate about a common axis. It is also preferred that the guide elements on the auxiliary frame and on the operating construction are positioned on respective fourth and fifth axes which run parallel to the axes already mentioned.
In order to keep the hand truck as simple as possible, it is preferable that the distance between the second and the third axes is equal to the distance between the third and the fifth axes. In this context it is also advantageous that the distance between the first and the third axes is equal to the distance between the third and the fourth axes.
To provide the hand truck with adequate robustness, it is preferable that the operating construction is provided with at least one transverse element by means of which its said legs are attached to one another. Furthermore, the auxiliary frame can be provided with at least one transverse element by means of which the said legs thereof are attached to one another.
To ensure that the goods are not accidentally pushed off the platform during transport, it is important that the hand truck is provided with a locking mechanism by means of which the pusher plate can be locked in one of the extreme positions, which locking mechanism is coupled to a control mechanism that is located on the operating construction, the coupling components between the locking mechanism and the control mechanism being located in hollow parts of the operating construction. On ergonomic grounds it is desirable that the control mechanism is so positioned that it is easily accessible to the user.
In a preferred embodiment the pusher plate is constructed as a flat plate with flanged edges. Furthermore, the pusher plate is constructed as a preformed plate such that the pivot points about the second and fifth axes have been retained and/or all said axes run parallel.
It can be advantageous to shape the pusher plate in such a way that certain goods can be pushed off the platform more easily. In this context consideration can be given, for example, to a concave pusher plate which is particularly suitable for pushing off casks.